Internal combustion engine system, comprising an internal combustion engine and an exhaust gas recirculation circuit

Abstract

An internal combustion engine system including an internal combustion engine and an exhaust gas recirculation circuit connecting an exhaust manifold of the engine to an intake manifold of the engine, the circuit including at least one reed valve, an EGR valve, that is arranged downstream of the reed valve on the path of exhaust gas flowing from the exhaust manifold to the intake manifold and an EGR line connecting the reed valve to the EGR valve. The system further includes a bypass line for gas, connecting the EGR line to an exhaust line of the engine and controller for controlling the flow of gas discharged through the bypass line.

The invention claimed is: 
     
       1. An internal combustion engine system, comprising an internal combustion engine and an exhaust gas recirculation circuit connecting an exhaust manifold of the engine to an intake manifold of the engine, the exhaust gas recirculation circuit comprising:
 at least one reed valve; 
 an EGR valve arranged downstream of the reed valve on a path of exhaust gas flowing from the exhaust manifold to the intake manifold; 
 an EGR line connecting an outlet of the reed valve to an inlet of the EGR valve, wherein the system further includes:
 a bypass line for gas, connecting the EGR line to an exhaust line of the engine; and 
 a controller for controlling the flow of gas discharged through the bypass line via controlling an opening position of a discharge valve positioned in the bypass line. 
 
 
     
     
       2. The system according to  claim 1 , wherein the discharge valve is a two-way valve. 
     
     
       3. The system according to  claim 1 , further including:
 a pressure sensor for measuring a pressure in the EGR line; and 
 a transmitter for transmitting the measured pressure to the controller. 
 
     
     
       4. The system according to  claim 1 , wherein the controller is configured to open the discharge valve when the pressure in the EGR line exceeds a predetermined threshold. 
     
     
       5. The system according to  claim 4 , wherein the controller is configured to maintain the discharge valve in the opening position for a predetermined period of time or until the pressure in the EGR line decreases down to a specific pressure value that is superior to a pressure of air in the intake manifold. 
     
     
       6. The system according to  claim 1 , wherein the discharge valve is an electromechanically operated valve. 
     
     
       7. The system according to  claim 1 , wherein the system further includes a turbocharger comprising an air compressor and a turbine for driving said compressor, the turbine being arranged so that the exhaust gas in the exhaust line flows through the turbine. 
     
     
       8. The system according to  claim 7 , wherein the bypass line connects to the exhaust line at a position downstream of the turbine on the path of exhaust gas flowing in the exhaust line. 
     
     
       9. The system according to  claim 7 , wherein the turbine is without waste gate. 
     
     
       10. The system according to  claim 7 , wherein the turbine is a fixed geometry turbine. 
     
     
       11. The system according to  claim 1 , wherein the exhaust gas recirculation circuit also includes a cooler. 
     
     
       12. The system according to  claim 11 , wherein the cooler is arranged upstream of the reed valve on the path of exhaust gas flowing from the exhaust manifold to the intake manifold. 
     
     
       13. The system according to  claim 11 , wherein the exhaust gas recirculation circuit includes a bypass of at least one of the cooler and the reed valve. 
     
     
       14. A vehicle comprising an internal combustion engine system comprising an internal combustion engine and an exhaust gas recirculation circuit connecting an exhaust manifold of the engine to an intake manifold of the engine, the exhaust gas recirculation circuit comprising:
 at least one reed valve; 
 an EGR valve, that is arranged downstream of the reed valve on the path of exhaust gas flowing from the exhaust manifold to the intake manifold; 
 an EGR line connecting an outlet of the reed valve to an inlet of the EGR valve, wherein the system further includes:
 a bypass line for gas, connecting the EGR line to an exhaust line of the engine; and 
 controller for controlling the flow of gas discharged through the bypass line via controlling an opening position of a discharge valve positioned in the bypass line.